Traditionally, solar modules have been mounted onto buildings with the modules angled to the south (when in the Northern Hemisphere). Lately, however, solar arrays have also been built with their photovoltaic modules angled in alternating rows facing to the east and west. In these “east-west” systems, the module rows are thus laid out with the array having alternating peaks and valleys (formed where the upper and lower sides of the angled modules meet one another). Surprisingly, such east-west arrays may actually generate more power over the course of the day, and also typically generate such power at more convenient times during the day. Specifically, such east-west systems lengthen power production time and eliminate traditional mid-day power spikes.
When wind passes over arrays configured with alternating peaks and valleys, low pressures are generated above the array, thereby causing lift forces on the array. Adding excessive ballast to the roof is inconvenient since the ballast must be both lifted up onto the roof and then moved around by the installers. In addition, rooftops also have weight limitations. Alternatively, fastening east-west systems directly to the roof has the disadvantage of causing roof penetrations which are expensive and potentially compromise roof integrity. Also, roofs have a maximum safe load which can limit the amount of photovoltaics used on the roof.
What is instead desired is an east-west system with improved aerodynamics (i.e.: one that generates less lift when wind passes thereover) such that excessive ballasting is not required. Preferably, such a system would also be lightweight, flexible, and fast and easy to assemble, making it easy for installers to assemble it on the roof. In addition, such a system would ideally be designed to accommodate thermal expansion and contraction of the panels themselves. In addition, such a system would ideally be designed to simplify grounding of the modules. Preferably, the system would also balance stiffness in order to get load sharing between components during wind events, yet also not be too stiff in order to accommodate roof pitch changes and mange thermal strains. To date, such a system has not been realized. As will be shown below, the present design provides such a desired system.